Files
linuxkit/kernel/patches-4.4/0035-Drivers-hv-vmbus-avoid-unneeded-compiler-optimizatio.patch
Rolf Neugebauer 201f89de74 kernel: Update to 4.10.9/4.9.21/4.4.60
Signed-off-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
2017-04-09 22:50:18 +01:00

40 lines
1.4 KiB
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From 47d06a1c2849f5c3560907404618744e609c9b38 Mon Sep 17 00:00:00 2001
From: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: Fri, 26 Feb 2016 15:13:18 -0800
Subject: [PATCH 35/44] Drivers: hv: vmbus: avoid unneeded compiler
optimizations in vmbus_wait_for_unload()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Message header is modified by the hypervisor and we read it in a loop,
we need to prevent compilers from optimizing accesses. There are no such
optimizations at this moment, this is just a future proof.
Suggested-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Radim Kr.má<rkrcmar@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit d452ab7b4c65dfcaee88a0d6866eeeb98a3d1884)
---
drivers/hv/channel_mgmt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index f70e35278b94..c892db5df665 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -605,7 +605,7 @@ static void vmbus_wait_for_unload(void)
bool unloaded = false;
while (1) {
- if (msg->header.message_type == HVMSG_NONE) {
+ if (READ_ONCE(msg->header.message_type) == HVMSG_NONE) {
mdelay(10);
continue;
}
--
2.11.1